


Beauty in Fleeting Steadfastness

by erihan



Series: PersonaL Monsters [1]
Category: Persona 5
Genre: Eldritch abomination butler yusuke au, M/M, kamoshida gonna die horribly later
Language: English
Status: Completed
Published: 2019-10-09
Updated: 2020-09-29
Packaged: 2020-11-29 09:56:19
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 4
Words: 4,713
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20961881
Author URL: https://archiveofourown.org/users/erihan/pseuds/erihan
Summary: Yuuki has become the main target of kamoshida's pettiness after Ryuji was put into a coma, in desperation he summons a very being to aid him in bringing the crooked teacher down. and quite possibly falls in love with someone whose true form is a ball of tentacles and eyes.





	1. Chapter 1

**Author's Note:**

> Yusuke here is inspired by the Monster Girl Encyclopedia's version of Shoggoth, however this work will not be nsfw. It will however have Kamoshida die horribly in a few chapters so theres that to look forward to

The volleyball hit Yuuki right in the face, the force behind it sending him stumbling to the floor. While normally this would be considered a foul, however the king of the court made them play by his own special rules.

“Get up, I said no outs till s you've hit back at least one toss. All of you can't return for shit.”

The room was dead silent aside from the panting from those who had exhausted themselves trying to meet his brutal expectations. Kamoshida wasn't someone you could stand against, especially since the incident with Ryuji just six months ago. So Yuuki sighs, dusts himself off and gets back up, no parents home to worry about the new bruises on his face and nothing to look forward to outside of his daily visit. Hopefully the teacher would get bored of beating them up and let them go before the commuter rush at the train station. 

Of course it took three more times of being sent to the floor before Kamoshida was satisfied, the man seemed to take joy in his torment and abuse. Most likely because he's the only one that still bothers visiting Ryuji. The train was crowded and the wait to actually be allowed in to see his friend was a bit longer than usual too due to it being a Friday. 

Ryuji however was unchanged, sleeping his days away in that white room without any idea of how bad things have gotten without his bright presence serving as a shield. A small voice inside Yuuki”s head wishes he would stay like this, and not have to deal with that man who had hurt him so badly ever again.  
One punch.  
One punch was all Kamoshida needed to claim self defense and return with a single one of his own that sent Ryuji into a coma. If that wasn't bad enough the bastard had done it in front of Yuuki's horrified eyes. What was supposed to be routine warm up stretches before the teams’ practice became a nightmare.

He shakes his head and changes out the flowers, he had done his best to put as much color into the hospital room as possible so in the offhand chance Ryuji wakes up while hes not there, he would wake up among color and signs people did care about him.There was something new on his bed, next to the worn teddy bear his friend’s mother had brought from home was a pink plush...crow? It bore a heart in its beak and its soft fluffy body was absolutely stuffed to make it as chunky as possible. However there was no note or indication of who could have sent it. Ryuji really didn't have any close friends other than Yuuki, so he can only conclude it was from one of the nurses.

“It's probably a good thing you were asleep today, Kamoshida would have thrown a fit if you returned the ball to him. I'm going to have to buy more concealer soon too.”

There's no reply, but he doesn't expect any, if his friend can hear him that would be wonderful, but if not it helps Yuuki’s own peace of mind to talk about his day like this. And if he closes his eyes he can pretend it's just another day walking home after school complaining about the things that man got away with. 

“Do you remember that book I talked about? The one I found in that antique shop? I'm thinking about doing the ritual in it..You would probably try to talk me out of it, but there's no harm in trying. The few adults at our school that want to help cant, and it seems like he's getting worse everyday. Besides it probably won't work, so don't worry bout it okay? If it works ...Kamoshida won't be able to hurt us anymore, and if it doesn't there's no harm done. I'm going to go home now okay? I’ll come and see you tomorrow too.”

“Shoggoth” The book describes it as a servile wish granter that only wants to experience the wonders of the mortal world, it seemed too good to be true, but honestly he’s sick of coming home with bruises and hoping against the odds that ryuji actually wakes up.The picture shows it as a small and cute girl with inky blue skin and gem like eyes in a maid’s uniform, though a closer inspection shows the black dress to be part of her body and the supposed gems inset into broaches and bracelets to be eyes...its mildly disturbing so he averts his eyes.

To summon one, he has to do the ritual by the light of the full moon tonight; the rooftop of his apartment should suffice. It was painful burning up old family photos as a beloved sacrifice, but he wants to do this with sincerity since the creature will be with him for a lifetime, if Yuuki is lucky one of them will take the deal and come to him, all he has to do is call out his wish.

“Please, come to me and lend your strength to stopping that tyrant from doing as he pleases!”

A minute passes, then two, then five and even ten...and all he can do is sigh and bite back a bitter laugh that he was foolish enough to do what a silly old book told him. He turns his back on the crudely drawn ash circle and goes to head back to his apartment; he will clean it up in the morning.

What greets him within what should have been his empty apartment is...monstrous. No small delicate girl but a writhing and shifting mass of tentacles with countless luminous yellow eyes winking in and out of existence as they pleased. The whole thing seems to be coated in and dripping a rainbow fluid that Yuuki is fairly sure is staining the carpet in ever changing colors. It doesn't make sense, something that big simply cant fit into his living room, in fact the room doesn't even seem to be his living room anymore but some other place thats both familiar and not. The creature, Shoggoth his mind helpfully provides despite the panic, looms closer to him without moving an inch, it simply moved the room around them.

“Tell me mortal, does everything in your world have such fascinating fixedness?”

“Y...Yes? They're supposed to…”

“Marvelous, I accept your offering. My service for yours.”  
There's no way Ryuji would ever believe this.


	2. Chapter 2

**Summary for the Chapter:**

> Akechi finally shows up in person

**Notes for the Chapter:**

> Probably just one more chapter...maybe since ryuji still has to wake up and Kamoshida is still alive

The Shoggoth’s name was simplified to Yusuke, and his first attempt at a human form will haunt Yuuki”s nightmares for the rest of his life. The second attempt faired better, a vague humanoid shape made of tentacles, then he became a vague human shaped mass with a fox mask for a face. Finally Yuuki decided to just suck it up and bright in his beloved maid and butler magazines for reference, he doesnt need anymore nightmare fuel.

“Fascinating, I wouldn't expect humans to separation even the garments that adorn them by sexes. Does this mean I cant wear this wavy piece of cloth in the front?”

“An apron? You can wear whatever you want as long as you look like a human.”

Theres a sound that might be humming from multiple throats before Yusuke stands before him in a vested butler outfit and apron ...just inky blue.

“You gotta pick a normal skin color.”

“But this woman has emerald skin!”

“Its just body paint, I guess the eyes are fine at least.” 

Especially with how he acted Yuuki was pretty sure he could just pass it all off as severe high school Chuuni, especially with all those ridiculous poses the Shoggoth is making. The room seems to have gone back to normal too, which is a relief, the constant color shifts were making the start of a migraine brew. Now...he just needed to figure out what exactly to do with Yusuke. He cant come to school with how he speaks and acts. But it wouldnt be fair to make him stay in the house all day either….

“I’ll figure out what you can do in the morning, can you eat food?”

“I dont know. Ive never eaten human food in the customary way before.”

“Guess we’ll find out then.”

The answer was a resounding yes with a very traumatizing result of several smiles appearing all along his new guest’s body. At least sleep seemed to come naturally to the shoggoth, all eyes closing and his temporary form going slack. Yuuki changes and slides into the other side of the bed, something about the contract including “getting to experience closeness as corporeal beings”, which honestly he had no problem with. Yusuke's body was about as warm as would be normal for a person, and surprisingly not moist or sticky like this true form seemed to be. Yuuki”s mind helpfully reminded him of all the tentacles too and he shakes his head before cuddling close. Tomorrow is the start of the weekend so hes decided the way hospital is the perfect place for Yusuke to start his blending in practice. 

It didn't really go disastrously as he thought it would, the gawking and needing to touch everything was easily explained as Yusuke being a country bumpkin foreigner. He only tried to eat someone’s keychain once, and was transfixed by the view from the train window the rest of the time. Yuuki knew the hospital would be a challenge, despite reassurances that it would go alright despite there being no identification for the shoggoth butler. A few elderly people and kids in the reception room stared of course, but the receptionist herself didn't even pay any mind to his companion, only saying someone else was currently visiting his friend so he should behave himself around them.

Said visitor was a young man in a pink sweater and oddly long scarf, Yuuki has to avert his eyes when he notices the sweater has a peekaboo window across the chest. 

“i...I’m sorry, I can come back later.”

“I couldnt possibly chase you away, you’re my dear Hero’s friend after all.”

“Hero..?” Was this guy alright in the head?

“Of course theres also the fact that eldritch abomination by your side will try to tear my head off if I made you sad most likely.” The grin that splits his face has a feral quality to it.

“Yusuke..?” Said person had pushed himself in front of his human charge.

“A Houri, a pigeon of the Goddess of Love who flock around “heroes”. Your friend must have done something very dangerous or brave if this lovestruck featherbrain is here.”

“How rude, I’m not here to fight...However, just for today I will retreat, my publisher will be angry if I miss my deadline again. Farewell little tamer of monsters.”

The guy left as quick as the wind, leaving behind yet another plush, this time a pink cat...maybe he just likes dressing like Valentine’s is every day. Yuuki shakes his head and makes sure all the flowers and the blanket are properly in place. He has to smack a rose out of Yusuke’s hands before a bite can be taken out of it, but otherwise its all normal. 

“Ryuji, I got someone to introduce to you, but before that...you got an admirer. And! He seems to be a writer, anyway this is Yusuke, the book actually worked.”

“Greetings, best friend of my master. I will happily make your acquaintance when you awaken.”

Routine surprisingly came easily, Yusuke picked up a job as an actual butler character at a cafe near the school, his looks AND his eccentric personality proving to be popular. Yuuki figured there was no harm in it since after the incident at the ice cream parlour the Shoggoth simply erased the memories of any unfortunate traumatized witness to his more human side. Ryuji’s admirer also finally introduced himself as the romantic crime novelist Goro Akechi. (Yuuki would deny that he got a copy of one of the books signed if anyone asked.) And Ryuji slept on while Kamoshida kept at his usual antics. It still hurt to get pummeled with a volleyball, but theres now someone waiting at home for him. Yuuki could bear it, he had to bear it. He witnessed the time Yusuke and the other nonhuman squared off for fun, surely Kamoshida wasnt horrible enough to warrant something like that?

Of course as he would soon find out, the man was far more vile, and Yusuke cared for him far more than he could imagine.


	3. Chapter 3

**Summary for the Chapter:**

> Kamoshida gunna die

**Notes for the Chapter:**

> Hooray this is done, gonna move on to the four other prompts I got from the discord group but might come back with an Akechi side later

Yusuke has enjoyed every single moment in the mortal plane thus far, it was a far cry from his own plane where constant change became almost a fixed state as paradoxical as it seemed. It was incredibly relaxing to be able to stop and smell a rose and not have it change scent and color every second. He was even somewhat getting the hang of the job he picked up to pass time by, the cafe was a good source of entertainment in the form of human observation. The shoggoth has even taken up a hobby known as sketching; putting pencil to paper and freezing a moment or form upon it. Nothing was more wonderful than discovering he could capture the moment exactly without it warping or changing. There was only one small problem interrupting his blissful life; his cute little master was being hurt by someone.

Yuuki might have tried to cover the bruises with the paste called makeup, but the hue didn't quite match due to the dark bruising underneath. He was summoned for the purpose of protecting his little master so he just can't let it continue on or it would make a mockery of his promise. Its shockingly simple for him to sneak onto the campus by mimicking the form of the clothes his master always wore to the place. Yusuke is half determined to check for all possible security breaches when a conversation catches his ears. 

“You would think he would go easy on us after that last win. Kamoshida Sensei is the worst.”

“It has to be Mishima”s fault, he missed that simple pass.”

“No wonder he's always having to stay behind and clean up.”

“Excuse me young misses, would you be kind enough to point me out to where Yuuki is?”

They told him easily enough, apparently his chosen appearance was aesthetically pleasing to others as well. How delightful...is what Yusuke was thinking, however when he arrived at the gym Yuuki was nowhere to be found. Only some ridiculously muscled humans who frowned upon seeing him. Clearly he has bad taste if he can't appreciate the beauty Yusuke carefully formed. 

“I was told Yuuki would be here.”

“Who the hell are you? That slowpoke is out running laps as punishment.”

He tilts his head and regards the human carefully, although he promised not to listen in, he has heard Yuuki talk about this “Kamoshida” to his unconscious friend before. The man’s soul sings of pride, greed, and lust with an undercurrent of violence. A barbarian that only believes in might is right in other words. Yusuke had been considering simply talking to the man in his comfortable half form to make him realize his errors in judgement, but with that disgusting stench making up his soul and the heard of previous misdeeds it would be best to just deal with him here and now.

Kamoshida thought things would just go as normal, bully some weakling students then go home and have a beer and a good wank to the girls locker room feed he had set up...and then a weirdo had walked into *his* gym looking for the runt. He thought it would just take some simple intimidation through words or flexing since he was on thin ice with the principal over Sakamoto. But the guy just frowned when he told him to leave...and then his skin seemed to seep into an inky blue like pigment had seeped through blotting paper. Arms legs, even the clothes upon his body seemed to split apart into many writhing tentacles. Golden lights, no eyes rising to peer through the void between the multitude of limbs, and throughout the whole horrifying transformation that handsome face remained where it was. He was so distracted by the transformation in front of him he failed to notice his surroundings till, backing up, something solid hit the back of his legs where empty court should have been.

“What the fuck is happening?! What the hell is this shit?!” 

“Such bad language, and to top it off you cannot even see the beauty that surrounds you?”

To Kamoshida there was no beauty, they were in what looked like a swamp made out of fog and seaweed, a strange sodden log was what his legs had caught on. The horrible being in front of him seemed to sigh and even more of those repulsive tentacles spread out of his body and reached forward. The p.e. teacher decided he had enough and ran. Rainbow puddles he jumped over, drooping branches that felt like fire when he pushed them away, and other more outlandish things that his mind was reeling in attempts to figure out all got in his way. The freak was just walking though, and Kamoshida is fast, he's confident he can get away...till his face slammed into the far wall of the gym in the middle of the swamp. 

“What did I do? You have no right to trap me in this place!” He's almost foaming at the mouth…

To his horror, there's a reply from a handsome smiling face that looks far more like a mask perched upon an only vaguely humanoid figure. 

“I would say hospitalizing one of your students is reason enough, that featherbrain told me he would have died without interference.” 

“Sakamoto swung first! It was self defence, no one can say I was wrong!”

The figure glided over the murk, closer, closer with that horrible porcelain face finally losing its grin, Kamoshida couldn't decide if he missed it compared to the seething fury contained within the glowing eyes and even lips that seemed to sneer. It did not say anything this time, and seemed to judge him within the all consuming silence. This...this abomination that only pretended to be a human was daring to judge him. No one would blame him if he killed it in self defence, it was just a monster wearing a human shaped mask that was tormenting him for no good reason other than it could. Kamoshida drew his fist back with all his might and swung. He cackled when a cracking sound came from the impact and the figure of the monster staggered. 

His glee turned to sheer horror when his hand was stuck fast within the creatures head and no amount of strength could budge it free. The cracked mask separated and reformed higher, looking him dead in the eye. And his blood ran cold, how could it not when this creature saw his struggles as nothing more than momentary amusement? More and more snake like limbs split out and wrapped around his body immobilizing him. 

I could take hundreds upon hundreds of years to slowly squeeze the life out of you, however Yuuki promised we were going to get something called “Konpeito” once he has finished with school, so I will make this quick.” 

Despite the promise to speed things up Yusuke made sure the man was conscious until the very last moment, that he felt every last one of his bones start to be ground to powder and his organs paste. He didn't eat the body however, merely sent it adrift in his home plane for someone with less...refined tastes to make a meal of. Then it's a matter of restoring the gym to its proper state, albeit much more clean than it was prior, it's like the janitor never even bothered to wax the floors. 

Yuuki had finished his final lap and changed back into his normal clothes, expecting Yusuke to be waiting at his cafe or home and having to do a double take seeing him at the gate. 

“Did you copy my uniform?”

“One of my coworkers said my uniform would draw too much attention if I went on a date with you in it.” He was pleased to see his master’s cheeks redden.

“Well..yeah but…”

“But?”

“Nothing, I’ll have to teach you about casual clothes later.” 

Konpeito was delightful, a truly beautiful confection that only humans could come up with. Yusuke thought he couldn't possibly find anything more wonderful in the world. 

And then he saw the tears of joy that Yuuki shed the day Ryuji woke up, his little master doing his best to restrain himself and not squeeze all the air out of his friend’s lungs. A glance sideways to Akechi showed his fellow nonhuman was thinking the same thing, smiles softly spreading on their faces as they both watched the humans they loved. They would protect both with all their might, and may anyone who would do them harm rue the day they were born in this truly admirable beautiful yet ugly world.


	4. Chapter 4

**Summary for the Chapter:**

> The Promised Lewds, except its less lewd and more existential crisis and love confessions   
Tentacles are involved to a degree tho

“Are you absolutely sure you understand Yusuke?”

“Of course, those videos were excellent research material. I didn't expect humans to be so creative when it comes to erotica as to find even those that resemble some of my kin as partners.” 

“You would be even more amazed if you could figure out how to use a computer without destroying it somehow.”

“Perhaps. Shall we begin?”

“No staining the actual rug this time, my parents might come home.”

“I sincerely doubt that, they’ve only texted you the whole time I’ve been with you.”

Yusuke doesnt let the conversation continue, instead pulling both of them into a pocket dimension made entirely of tentacles sparkling in various colors. He feels proud of himself that he remembered that color shifting was hard on mortal eyes, all of them being lovely shades of blue. This whole thing started because that pink feather brain had bragged about getting to something called “third base” with his Master’s best friend. He would show him that he could do that too...but just unleashing his tentacles on his Master was met with a forehead smack and no snacks for a whole week. And then there were the research videos, he learned far more about human sexuality than talking to his fellows who had mortal world experience had been able to convey to him. 

“Is the color alright?”

“It's pretty, I’m glad you didnt make this place all foggy and muddy.”

“You liked the sparling one with the magical girls best.”

He shows off by having the tentacles move to get the mortal clothing off his shell, Yusuke would be keeping it intact for the “mood”. To the extent he had thoroughly studied human male anatomy and crafted the most beautiful equipment possible based on the references. And it's what will be going inside his Master, all the references seemed insistent that it should be otherwise, but he had made it just for Yuuki.

One, to lift him up. 

Two, to slip off his clothing. 

Three, to give him the full view.

“To make it clear, we aren't going with the aphrodisiac method this time, correct?”

“Of course not, I want to remember properly at least for this first time.”

Ysuke hums happily and stuffs two soft tentacles inside that cute little mouth, sweet golden juice that replicates the flavor of the mango fruit trickles inside. Thematically and visually, it's doing wonders for him. Must be that he's becoming more in sync with his carefully crafted mortal shell, good. He finds his face shifting into a “smile” as he shoves two fingers into that already stuffed mouth, taking his time and savoring the sound as he gently shoves them in and out to get them as slick as possible before moving the hand downwards. This they had already practiced before, when watching the reference videos. 

“Soon, we will be joined in the mortal way. I believe it's the custom to share an oath first.” 

“I promise, I shall stay with you your entire life.” A kiss to Yuuki’s forehead as the tentacles shift from his mouth to supporting his head.

“I will cherish every ephemeral moment.” A second one to his left cheek even as his Master keens softly from him teasing that spot inside him.

“I will give you all that I have.” The tentacles shift both of their positions to be much more convenient, hand slipping out, and he kisses the right hand next.

“And when your time comes, I will not let a mortal death claim you, but rather take you with me to spend eternity in happiness.” Gently, with as much affection as his body contains, Yusuke kisses Yuuki on his lips.

“Master, Yuuki, do you pledge to be mine till time freezes to pieces and melts away?”

An adorable blush, and eyes...wet? He doesn't understand why his little Master is crying at this moment. Yuuki’s mouth is curved into a smile so sharp it must hurt his cheeks, so why is he crying???

“Did I-”

“Yusuke, I already promised all of that back when I summoned you.”

“Yes, well-”

“Of course I want to be with you.” Ah, a soft pressing of their lips once again, this time he wasn't the one initiating it. Yusuke hums and leans into it.

“If you understand, hurry up and put it in, I'm aching for you.” 

“As you wish.” 

Humans were warm inside, it was a different warmth than the red remains of that teacher. For one he would never want to hurt his dear Yuuki. Yusuke finds his own breath quickening and his pulse? That was new, it was pounding inside his crafted shell, double time what he imagines it sets at normally if he was a true mortal. His movements grow erratic at the thought, tentacles moving to wrap around his own body and stabilize the pace. Subconsciously he's trying his best to make his Master feel as good as possible even as the rest of him has a minor crisis at the single instant he had thoughts of...envy that he wasn't born mortal himself. 

If he had been, would they have met, have grown so close as to join together like this? Would he be able to see exactly when Yuuki makes soft little gasps as he hits a particularly good spot? Would he be as eager to mark that pale throat up with proof of their belonging to each other? And his Master, would he have the same eager shifting, the same impossible tightness that strove to keep him deep inside as possible? Those fruitless circular thoughts are all washed away at the sight of Yuuki suddenly seeming to arc into a perfect angle away and yet still drawing him close as he climaxes in little spurts. 

Yusuke can't help but make a soft noise of regret as he cant _taste_ it from this position, and the tentacles senses aren't currently linked to him. However, the delicious warmth pulls his attention away, somehow it's embracing him tightly as if it can't bear to part. That paired with that beloved face turned towards him with eyes full of affection has him letting go and experiencing exactly what mortals meant by euphoria. The tentacles go slack immediately after, all thoughts in his mind muted to soft warm comfort, and limbs loose on top of Yuuki.

He's comfortable, and pleasantly surprised to discover upon kissing his Master that the sweet mango flavor has not faded away. Truly, it had been a most pleasant experience. There's a soft sigh as Yusuke rests his head on Yuuki’s chest, before the tentacles lower both of them down onto the bed back in the mortal plane and leave them be.

“Next time I would like to do it on here.”

There's a tired half snort of laughter.

“I love you.”

“As do I, till the last star has burned itself to cinders.”


End file.
